I would think twice about it. My main reason for saying this is contrast ratio.
Sony does not publish contrast ratios for these units, but I have found reviews that list it at 66:1 to 130:1, out of the box. The CS4 may be better, I couldn't find anything that listed it specifically. Since it uses the same 0.7" LCD panels, I suspect it is similar. The UHP lamp that these units use is skewed towards blue and on the "high" color setting has a color temperature as high as 11000K! Some of these shortcomings may be "tweaked" for improvement, for example, I use a red color correcting filter on my projector and a grey screen. The red filter blocks the excessive blue light component and the grey screen absorbs some of the light to give a better apparent contrast ratio. With these tweaks I would estimate that the contrast ratio can be improved to the 200:1 range.
Don't be intimidated by all this techno-babble, there are some very positve features; good vivid colors (especially when corrected and calibrated), low noise, good lamp life, low initial cost, good three year warranty.
I have used a similar VPL-CS1 for nearly two years and have been happy watching and tweaking it.